In the oil and gas industry, it is necessary to understand the properties of materials used during drilling and exploration and to determine how properties are affected by temperature, pressure and time.
Test cells are variously used to determine properties of chemical systems in relation to time, temperature, and pressure variations relevant to drilling and cementing operations.
During common laboratory testing procedures, mixtures are prepared, inserted in a test cell, and subjected to temperature and pressure variations. A commonly used laboratory device is a high temperature high pressure filter press, sometimes referred to herein as an HTHP filter press. Conventional test cells are generally constructed of stainless steel with upper caps and lower caps. HTHP filter presses are used to determine the characteristics of filtrates expelled under simulated down hole conditions of various fluids used in the industry, such as drilling muds, cement slurries, and completion fluids. Tests are run at temperatures as high as 500° F. and pressures up to 5000 PSI. Due to test design requirements and properties of the fluids being tested, plugging of pressurization ports can occur from time to time. Upon a plugging occurrence, high pressure gases and liquids (i.e., fluids) can be trapped inside the cell.
Currently-practiced methods to clear the plugged vent and release the pressure include using a paper clip or like object to punch through a vent and clear the obstruction, and operating a drill bit extending through a vent. Problematically, these and similar methods require manually clearing the vent and hoping the resulting pressure release, if any, will be not be explosive. Alternatively, elaborate safety stands may be constructed that allow the cell cap to be removed safely, while preventing damage or injury from explosive release of pressure. Currently practiced methods all potentially allow under-controlled release of gases, liquids, and debris.